speedometer question
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Joined: Dec 2007
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From: Clayton North Carolina
speedometer question
Just fired up my 81 after a 3 year resto project. Runs and looks great, however the speedometer cable bounces and makes a clicking noise. Did a search and could not find any info on this. The car has cruise, but I do not have it hooked up (vacuum lines capped)
Anyone experience this before??
Mark
Anyone experience this before??
Mark
Safety Car
Joined: Nov 2004
Posts: 4,359
Likes: 57
From: Mundelein Illinois
Car was famous for this.
You can try to grease speedo cables and making sure you have no tight bends in them or cruise module may need to be restored.
Most of the time it is the speedo itself, because of the 85MPH speedo didn't have much tension built into it. You won't have that problem with a 78 or 79 speedo that went to 140mph.
Good luck
You can try to grease speedo cables and making sure you have no tight bends in them or cruise module may need to be restored.
Most of the time it is the speedo itself, because of the 85MPH speedo didn't have much tension built into it. You won't have that problem with a 78 or 79 speedo that went to 140mph.
Good luck
Former Vendor
Joined: Aug 2006
Posts: 76,656
Likes: 1,850
From: Jeffersonville Indiana 812-288-7103
St. Jude Donor '08-'09-'10-'11-'12-'13-'14-'15
Just fired up my 81 after a 3 year resto project. Runs and looks great, however the speedometer cable bounces and makes a clicking noise. Did a search and could not find any info on this. The car has cruise, but I do not have it hooked up (vacuum lines capped)
Anyone experience this before??
Mark
Anyone experience this before??
Mark
Before you grease the cables read this from AC Delco. http://willcoxcorvette.com/repairand...lp.php?hID=283
Now you say the speedometer is clicking... Is the trip odometer stuck in the pushed in position? If so, try pulling it out.
Take the cable loose from the back of the transducer and with a drill run it up. See if you still have the tick and flapping. If you still have the problem there may be a problem in the upper cable or the speedometer.
The only way to isolate this is if you either pull the speedo and run it up with a drill or replace the speedo cable. If you need to pull the speedometer, you can use this to remove it... step by step... http://willcoxcorvette.com/repairand...lp.php?hID=146
Willcox Inc.
Team Owner
Joined: Jan 2006
Posts: 37,637
Likes: 3,114
From: Crossville TN
Word of caution: Run that drill slowly at first. You need to determine if you are turning the cable in the correct rotation. It doesn't take many RPM's to get the speedo to read. Just don't break it by overspeeding the speedo head.
Thread Starter
Advanced
Joined: Dec 2007
Posts: 89
Likes: 0
From: Clayton North Carolina
The odometer and the trip odometer are not registering any movement despite the fact that I have put approx 25 miles on the car since i fired it up.
I will check to see if it is stuck in. One note that I should mention, is for the first 2 - 3 miles I ran the car, the speedometer worked as if should, then just failed.
Mark
I will check to see if it is stuck in. One note that I should mention, is for the first 2 - 3 miles I ran the car, the speedometer worked as if should, then just failed.
Mark
Team Owner
Joined: Jan 2006
Posts: 37,637
Likes: 3,114
From: Crossville TN
Either the speedometer head, the speedo cable or the plastic drive gear in the transmission have failed. Check the other two possibilities before you dig into the speedo head. Use the drill 'test' to see if the speedo still works. While you have the cable accessible [for that test], see if it can be pulled out of the cable housing easily. It should be restained by the engagement mechanism at the speedo head; but if the cable snapped, it will pull right out.
Former Vendor
Joined: Aug 2006
Posts: 76,656
Likes: 1,850
From: Jeffersonville Indiana 812-288-7103
St. Jude Donor '08-'09-'10-'11-'12-'13-'14-'15
I will say that it is very rare for the speedo head in the 1978-1982 cars to go bad. It was a way better design than the head used from 1968-1977. If I was a betting man, I'd say the problem is in one of the cables which fail quite often on this same model year.
But... when you say the odometer and the trip are not working at all, is the needle still showing movement? If the needle is moving upward and the odometer is not moving then there would be problem in the head.
Do come of the checks listed above and then if it is the head let me know... I can fix this for you.
Willcox
But... when you say the odometer and the trip are not working at all, is the needle still showing movement? If the needle is moving upward and the odometer is not moving then there would be problem in the head.
Do come of the checks listed above and then if it is the head let me know... I can fix this for you.
Willcox
